• 한국주조공학회지
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• 제26권5호
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• pp.227-231
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• 2006

Liquid formability of bulk amorphous alloys is known to be very poor due to their high viscosity comparing with conventional metallic materials. It is important to have the fabricating technology of bulk amorphous alloys in order to make the components with complicated shape. Liquid formability includes the mold cavity filling ability and the hot tear(crack) resistance during solidification. A mold made of a commercial tool steel for the formability test was designed. Melting was performed by the arc melting furnace with melting capacity of 200 g in an argon atmosphere. Liquid formability and glass forming ability of Cu base and Ni base bulk amorphous alloys were measured and evaluated. Mold filling ability of Ni-Zr-Ti-Si-Sn alloy was better than that of Cu-Ni-Zr-Ti alloy, however the reverse is the hot tear resistance. Bulk amorphous alloy is very susceptible to crack if partial crystallization occurs during solidification. Crack resistance was thought to be closely related with the glass forming ability.

• Journal of Advanced Marine Engineering and Technology
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• 제19권2호
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• pp.56-66
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• 1995

Recently, with theraped advancement in th oceanology such an ocean-going vessel and oceanic structures, there is a need to study the cavitation erosion-corrosion control of pump impeller, the partial element of ocean machinery, for more effective operation. Especially, the cathodic protection (impressed current method & Al-sacrificial anode method) was applied to sea water, and Cu-alloy material mixed Zn & Al was used as a control method of cavitation erosion-corrosion. In this study, used the piezoelectric vibrator with 20KHz, 24.mu.m to cavity generation apparatus, and investigated the weight loss, weight loss rate, electrode potential & current density etc. under this condition. According to test result, thos describes how to indentify an influence of the cathodic protection and Al & Zn addition in material development for the control of cavitation erosion-corrosion, and those will serve as fundamental data on the cavitation erosion-corrosion control of oceanic centrifugal pump.

• Journal of Chest Surgery
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• 제27권4호
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• pp.259-265
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• 1994

Cor triatriatum is a relatively rare cardiac anomaly, whose major feature is a fenestrated membrane separating an upper common pulmonary venous chamber from a lower true left atrial cavity. Interatrial communications may be present between the right atrium and the common pulmonary venous chamber or the true left atrium. From April 1981 to April 1992, 24 patients with cor triatriatum were treated at Seoul National University Hospital. Ages ranged from 1 month to 24 years with mean of 7.4 years. Twenty patients had interatrial communications through a patent foramen ovale, primum or secundum defect of the atrial septum. Four had no interatrial communications. Fourteen patients had associated anomalies; partial anomalous pulmonary venous connection in 3, total anomalous pulmonary venous connection in 2, persistent left superior vena cava in 3, and other anomalies in 6 patients. Surgical corrections were performed through right atriotomy in 18 patients, left atriotomy in 4, and both atriotomy in 2. Three patients [12.5%] died early after operation; two of them were associated with single ventricle. Six out of 21 survivors [28.6%] experienced complications; recurrent pneumonia, pulmonary embolism, ischemic encephalopathy, diaphragmatic palsy and tachyarrhythmias. At the time of follow up, all survivors, except one, were in functional class I. Surgical correction of cor triatriatum restored normal hemodynamic status with relatively low operative mortality, especially in patients not complicated with severe anomalies. This report summarizes the clinical diagnosis, associated anomalies, interatrial communications, surgical approach and late result of 24 patients underwent surgical corrections in our hospital.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권4호
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• pp.322-326
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• 1992

Epiphora is overflow of tears due to obstruction of lacrimal duct. Dacryocystorhinostomy is the most common procedure to eliminate the epiphora secondary to complete or partial obstruction of the nasolacrimal duct. The procedure is to artificially create passage between lacrimal sac and nasal cavity. Especially, epiphora would be accompany often by nasolacrimal duct obstruction when trauma of oromaxillofacial area lead to nasal fracture, medial wall fracture of orbit. Therefore in this case there are many case to perform dacryocystorhinostomy because probing and tubing is difficult to resolve the epiphora. We performed 4 cases of dacryocystorhinostomy for adult nasolacrimal duct obstruction from May 1991 to October 1991. The results were very satisfactory in all the case. Epipora disappeared in all case.

• Investigative Magnetic Resonance Imaging
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• 제19권1호
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• pp.10-18
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• 2015

Background and Purpose: The association between the low emotional regulation and the brain structural change of major depressive disorder (MDD) has been proposed, but the voxel-based morphometry (VBM) studies on female MDD are rare. The purpose of the present study was to show the regional volume changes of gray matter (GM) in female patients with MDD by optimized VBM. Methods: To control subjects homogeneity, twenty female MDD patients and age, sex matched 21 normal controls were included for the VBM analysis. To identify the change of regional gray matter volume (GMV), the optimized VBM was performed with T1 MRIs. The amounts of gray/white matter and intracranial cavity volumes (ICV) were measured. The analysis of covariance (ANCOVA) and partial correlation analyses covariate with age and ICV were applied for VBM. Results: The age and ICV distributions were similar between the two groups. In the ANCOVA, the total GMV of MDD was smaller than that of normal controls. In the VBM, regional GMV was relatively decreased in the limbic system (amygdalae, ambient gyri, hippocampi heads, subiculum, posterior parahippocampal gyri, pulvinar nuclei, dorsal posterior cingulate gyri, and left pregenual cingulate gyrus). The lingual gyri, short insular gyri, right fusiform gyrus, and right inferior frontal gyrus were also showed decreased regional GMV. Conclusion: The results of this study indicate that the female MDD is mainly associated with the structural deficits of the limbic system and limbic system related cortices, which were known to the center of emotions.

• 대한두경부종양학회지
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• 제35권2호
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• pp.39-43
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• 2019

Peripheral giant cell granuloma (PGCG) is an benign non-neoplastic lesion most commonly occurring in oral cavity but extraoral PGCG is extremely rare. Recently, we experienced a case of an isolated PGCG in the parotid gland in 59-year-old man. FNAB findings and radiologic findings including CT and US were suggestive of Warthin's tumor. Partial parotidectomy was performed. Pathologic findings showed fibrillar connective tissue stroma with spindled, ovoid, and round histiocytes-like cells mixed with uneven multinuclear giant cells, small capillaries, hemorrhage, hemosiderin-laden macrophages, and necrosis which were consistent with giant cell granuloma. We report a case of an PGCG in parotid with a review of literature.

• International Journal of Fluid Machinery and Systems
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• 제3권1호
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• pp.50-57
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• 2010

The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance. Cavitation surge oscillation, however, often occurs at partial flow rate and extremely low suction pressure. As the cavitation surge oscillation with low frequency of about 10 Hz occurs in a close relation between the inlet backflow cavitation and the growth of blade cavity into the throat section of blade passage, one method of installing an axi-asymmetrical plate upstream of inducer has been proposed to suppress the oscillation. The inlet flow distortion due to the axi-asymmetrical plate makes different elongations of cavities on all blades, which prevent the flow from becoming simultaneously unstable at all throat sections. In the present study, changes of the suppression effects with the axial distance between the inducer inlet and the plate and the changes with the blockage ratios of plate area to the cross-sectional area of inducer inlet are investigated for helical inducers with tip blade angles of $8^{\circ}$ and $14^{\circ}$. Then a conceivable application will be proposed to suppress the cavitation surge oscillation by installing axi-asymmetrical inlet plate.

• Journal of Korean Neurosurgical Society
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• 제45권6호
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• pp.381-385
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• 2009

The first case of intracranial metastases of a cervical intramedullary low-grade astrocytoma without malignant transformation in adult is presented in this report. Seven years ago, a 45 year-old male patient underwent biopsy to confirm pathologic characteristics and received craniocervical radiation and chemotherapy for a grade II astrocytoma in the cervical spinal cord. Two years later, posterior fusion was necessary for progressive kyphosis in the cervical spine. He was well for approximately 7 years after the primary surgery. Two months ago, he presented with partial weakness and incoordination with gait difficulty. MRI Scan demonstrated multiple small lesions in the cerebellar vermis and left hemisphere. After suboccipital craniectomy and posterior cervical exposure, the small masses in the cerebellar vermis and hemispheres were excised to a large extent by guidance of an intraoperative navigation system. The tumor at the cervical and brain lesions was classified as an astrocytoma (WHO grade II). When a patient with low-grade astrocytoma in the spinal cord has new cranial symptoms after surgery, radiaton, and chemotherapy, the possibility of its metastasis should be suspected because it can spread to the intracranial cavity even without malignant transformation as shown in this case.

• 대한수의학회지
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• 제61권1호
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• pp.9.1-9.6
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• 2021

Factors such as location, volume, and the type of neoplasm complicate achieving tumor control. Electrochemotherapy (ECT) is a supplementary treatment for inoperable neoplasms in veterinary patients. Three dogs were diagnosed with a tumor. Two were squamous cell carcinoma (SCC), and the other was liposarcoma, each with a single tumor with the size range of 1 to 5 cm. The tumor locations were the cervical, oral, and abdominal cavity. ECT was selected as a treatment. Bleomycin was injected intratumorally at the dose of 0.5 to 1.0 mg/㎤. Five minutes after the injection, electric pulses applied in a sequence of eight pulses lasting 100 μsec each, were delivered in 1,000 V/cm. An evaluation was performed after 1 week, and the next session was administered 2 weeks later. In a patient with oral SCC, the tumor was in partial remission after two sessions of ECT. Another patient with SCC on her neck was showed complete remission after 2 weeks of ECT administration. A third patient showed stable disease for 8 weeks. Complications were mild and transient and included skin necrosis, edema, local pain, and gait disturbance. ECT is a valid adjuvant, especially for inoperable, cutaneous, or accessible intra-abdominal tumors.

• Journal of Korean Neurosurgical Society
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• 제46권5호
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• pp.479-483
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• 2009

Objective : A mouse model of spinal cord injury (SCI) could further increase our basic understanding of the mechanisms involved in injury and repair of the nervous system. The purpose of this study was to investigate whether methods used to produce and evaluate photochemical graded ischemic SCI in rats, could be successfully adapted to mice, in a reliable and reproducible manner. Methods : Thirty female imprinting control region mice (weighting 25-30 g, 8 weeks of age) were used in this study. Following intraperitoneal injection of Rose bengal, the translucent dorsal surface of the T8-T9 vertebral laminae of the mice were illuminated with a fiber optic bundle of a cold light source. The mice were divided into three groups; Group 1 (20 mg/kg Rose bengal, 5 minutes illumination), Group 2 (20 mg/kg Rose bengal, 10 minutes illumination), and Group 3 (40 mg/kg Rose bengal, 10 minutes illumination). The locomotor function, according to the Basso-Beattie-Bresnahan scale, was assessed at three days after the injury and then once per week for four weeks. The animals were sacrificed at 28 days after the injury, and the histopathology of the lesions was assessed. Results : The mice in group 1 had no hindlimb movement until seven days after the injury. Most mice had later recovery with movement in more than two joints at 28 days after injury. There was limited recovery of one joint, with only slight movement, for the mice in groups 2 and 3. The histopathology showed that the mice in group 1 had a cystic cavity involving the dorsal and partial involvement of the dorsolateral funiculi. A larger cavity, involving the dorsal, dorsolateral funiculi and the gray matter of the dorsal and ventral horns was found in group 2. In group 3, most of the spinal cord was destroyed and only a thin rim of tissue remained. Conclusion : The results of this study show that the photochemical graded ischemic SCI model. described in rats, can be successfully adapted to mice, in a reliable and reproducible manner. The functional deficits are correlated an increase in the irradiation time and, therefore, to the severity of the injury. The photothrombotic model of SCI, in mice with 20 mg/kg Rose bengal for 5 minutes illumination, provides an effective model that could be used in future research. This photochemical model can be used for investigating secondary responses associated with traumatic SCI.